David E. Ross wrote:
On 8/8/12 2:02 PM, mdemetri2 wrote:
Hi, I have been 4 years in my current home, and the back garden
pretty much each year needs some new plants and shrubs. Although I
admit we have in the past bought what looks nice and arent
necessarily suited for our east facing heavy clay moisture retaining
soil.

Firstly, I have over the last 2 months or so being contemplating
removing the soil/clay from our flower bed about a foot or so and
replacing with new soil mixed in with sand but adding more depth - so
allowing for a total of 15 inches of decent soil to replace the harsh
stuff we have now. Lots of digging out and replacing.....good idea?

What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

D

On 8/8/12 10:12 PM, David Hare-Scott wrote:
David E. Ross wrote:
On 8/8/12 2:02 PM, mdemetri2 wrote:
Hi, I have been 4 years in my current home, and the back garden
pretty much each year needs some new plants and shrubs. Although I
admit we have in the past bought what looks nice and arent
necessarily suited for our east facing heavy clay moisture retaining
soil.

Firstly, I have over the last 2 months or so being contemplating
removing the soil/clay from our flower bed about a foot or so and
replacing with new soil mixed in with sand but adding more depth - so
allowing for a total of 15 inches of decent soil to replace the harsh
stuff we have now. Lots of digging out and replacing.....good idea?

What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

D


At the end of the original message, mdemetri2 mentioned planting shrubs
and perennials. For those, this would indeed be a problem.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary

David E. Ross wrote:
On 8/8/12 10:12 PM, David Hare-Scott wrote:
David E. Ross wrote:
On 8/8/12 2:02 PM, mdemetri2 wrote:
Hi, I have been 4 years in my current home, and the back garden
pretty much each year needs some new plants and shrubs. Although I
admit we have in the past bought what looks nice and arent
necessarily suited for our east facing heavy clay moisture
retaining soil.

Firstly, I have over the last 2 months or so being contemplating
removing the soil/clay from our flower bed about a foot or so and
replacing with new soil mixed in with sand but adding more depth -
so allowing for a total of 15 inches of decent soil to replace the
harsh stuff we have now. Lots of digging out and
replacing.....good idea?

What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

D


At the end of the original message, mdemetri2 mentioned planting
shrubs and perennials. For those, this would indeed be a problem.

How are you going to remove the barrier 15in or more down, how deep does the
clay have to be amended, how will you know when you have done it and how
long will that take? Maybe the answer instead is not to use deep rooted
plants or to build up mounds several feet high.

D

On 8/9/12 4:34 PM, David Hare-Scott wrote:
David E. Ross wrote:
On 8/8/12 10:12 PM, David Hare-Scott wrote:
David E. Ross wrote:
On 8/8/12 2:02 PM, mdemetri2 wrote:
Hi, I have been 4 years in my current home, and the back garden
pretty much each year needs some new plants and shrubs. Although I
admit we have in the past bought what looks nice and arent
necessarily suited for our east facing heavy clay moisture
retaining soil.

Firstly, I have over the last 2 months or so being contemplating
removing the soil/clay from our flower bed about a foot or so and
replacing with new soil mixed in with sand but adding more depth -
so allowing for a total of 15 inches of decent soil to replace the
harsh stuff we have now. Lots of digging out and
replacing.....good idea?

What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

D


At the end of the original message, mdemetri2 mentioned planting
shrubs and perennials. For those, this would indeed be a problem.

How are you going to remove the barrier 15in or more down, how deep does the
clay have to be amended, how will you know when you have done it and how
long will that take? Maybe the answer instead is not to use deep rooted
plants or to build up mounds several feet high.

D


If the clay is treated with gypsum to make it more porous and if the top
foot of clay is tilled with new top soil, the interface between the top
soil and the clay subsoil will be blurred. Clay is often rich in
nutrients other than nitrogen. With careful use of fertilizer and with
infrequent but deep watering, plant roots will grow down below that
blurred interface into the clay.

My natural soil is heavy adobe clay. What I have suggested here is
based on my experience, especially my use of gypsum. Every year, I use
at least 50 pounds (23 kg) of gypsum in my garden; some years, I use 150
pounds (70 kg). Other than the obstructions caused by tree roots, I can
dig the soil quite easily; and my plants -- all perennials, shrubs, and
trees -- seem to thrive.

No, I do not have a large garden. My total lot is slightly less than
0.25 acre (0.1 hectare), including the footprint of my house and the
extreme slope that I describe at
http://www.rossde.com/garden/garden_back.html#hill.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary

"David E. Ross" wrote in message
If the clay is treated with gypsum to make it more porous and if the top
foot of clay is tilled with new top soil, the interface between the top
soil and the clay subsoil will be blurred. Clay is often rich in
nutrients other than nitrogen. With careful use of fertilizer and with
infrequent but deep watering, plant roots will grow down below that
blurred interface into the clay.

Given the amount of rain the UK has had over the past summer, watering is
probably not really needed. In fact it's possible that this area could end
up as I suggested - like a bog garden.

In article ,
"David Hare-Scott" wrote:

David E. Ross wrote:
On 8/8/12 2:02 PM, mdemetri2 wrote:
Hi, I have been 4 years in my current home, and the back garden
pretty much each year needs some new plants and shrubs. Although I
admit we have in the past bought what looks nice and arent
necessarily suited for our east facing heavy clay moisture retaining
soil.

Firstly, I have over the last 2 months or so being contemplating
removing the soil/clay from our flower bed about a foot or so and
replacing with new soil mixed in with sand but adding more depth - so
allowing for a total of 15 inches of decent soil to replace the harsh
stuff we have now. Lots of digging out and replacing.....good idea?

What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

D

Is that 15 inches "just spread", or after watering?

--
Welcome to the New America.
http://www.youtube.com/watch?v=hA736oK9FPg
or
E Pluribus Unum
Green Party Nominee Jill Stein & Running Mate, Cheri Honkala
http://www.democracynow.org/2012/7/13/green_party_nominee_jill_stein_running

On Thu, 9 Aug 2012 15:12:21 +1000, David Hare-Scott wrote:
What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

Yes, it can still be a problem. For instance, all the fertilizers and
all the minerals in your water that you dump
on the flower bed over the years -- the remains -- may become more
concentrated because they can't move past that X inches of "good soil",
and then you get plants in a saline soil, which collapsse and die.

What you're proposing makes a sort of giant flower pot. With a real
flower pot, you can tip it over at the end of a season, dump out the old
and replace the soil fairly readily. That's a whole lot more work with
a bed in the garden -- as much or more than you started the project with.


http://septictankinfo.com/Gayman_Clay.JPG is a micrograph of clay particles;
they are flat plates that tend to want to stack or shingle over each other,
forming water-impenetrable layers, particularly if there's enough sodium
in the soil or in what you add.

Treat clay soils with respect... they're difficult to grow on.

Kay

Kay Lancaster wrote:
On Thu, 9 Aug 2012 15:12:21 +1000, David Hare-Scott
wrote:
What you propose will create an interface between top soil and
subsoil. Many plant roots will not cross that interface.


OK but it is a flower garden this may not be a problem.

Yes, it can still be a problem. For instance, all the fertilizers and
all the minerals in your water that you dump
on the flower bed over the years -- the remains -- may become more
concentrated because they can't move past that X inches of "good
soil",

That is another reason that any made bed on top of clay has to have
drainage, whcih I had mentioned. It is a somewhat different issue to the
root barrier.

and then you get plants in a saline soil, which collapsse and die.

What you're proposing makes a sort of giant flower pot. With a real
flower pot, you can tip it over at the end of a season, dump out the
old
and replace the soil fairly readily. That's a whole lot more work
with
a bed in the garden -- as much or more than you started the project
with.


http://septictankinfo.com/Gayman_Clay.JPG is a micrograph of clay
particles; they are flat plates that tend to want to stack or shingle
over each other, forming water-impenetrable layers, particularly if
there's enough sodium
in the soil or in what you add.

Treat clay soils with respect... they're difficult to grow on.


yes indeed.

D

On 10/08/2012 00:27, David Hare-Scott wrote:
Kay Lancaster wrote:
Treat clay soils with respect... they're difficult to grow on.

yes indeed.

D

A commonly held and vastly mistaken view, IMHO. Difficult to work
maybe. But they are not difficult to grow on at all, if you keep to a
couple of simple rules. Firstly, never try to plant anything when they
are soaking wet. Secondly, never try to plant anything when they are
bone dry. Clay is far more suited to growing many plants than sandy
soil; even those naturally found in sandy environments will often more
than just tolerate clay. I have grown heathers without problem, and
grown and fruited blueberries on clay (pH 6 - 6.5). I have even been
able to move plants which are said to really dislike being moved because
a great lump of clay sticks to the roots, and, to all intents and
purposes, the roots really haven't been disturbed at all. Try that with
sandy or even "highly desirable" loamy soil. The one plant I have given
up with on clay soil is grass. Where it is constantly wet, a lawn
simply ends up a mess, often with more moss than grass. The previous
owner of the house I moved in to had so much trouble he installed land
drains, but even those couldn't make a meaningful difference and in the
end I had the lawn removed (no great loss as I can't stand lawns anyway).

I live in the Sussex weald, and have been gardening on clay for over 25
years. And, believe me, Sussex clay is real clay. I have about 10
inches of claggy "soil" over a solid clay subsoil (solid with ironstone
lumps, that is. Even a pickaxe fails to penetrate some parts. and I have
to resort to a hammer drill if I want a deep hole). The most difficult
thing about gardening on clay is digging the damn stuff; it is /very/
hard work. It even sticks to stainless steel spades with a vengeance.
And when dry, don't even bother with a hammer drill - it's not worth the
effort. Wait until it's workable again.

But when it grows stuff, it is brilliant. It holds moisture; it holds
nutrients; it anchors. It tends to help withstand frosts much better
than lighter soils.

--

Jeff

On 10/08/2012 00:27, David Hare-Scott wrote:
Kay Lancaster wrote:
Treat clay soils with respect... they're difficult to grow on.

yes indeed.

D

A commonly held and vastly mistaken view, IMHO. Difficult to work
maybe. But they are not difficult to grow on at all, if you keep to a
couple of simple rules. Firstly, never try to plant anything when they

I, too, have been growing on clay for about 40 years now... first the clay
subsoil that was all the builders left when they stripped the top soil
and sold it at my childhood home in Iowa, and now out here in Oregon --
both yellow clays, though the Oregon clay is calcium poor, rocky and
nearly free of worms (there are no native worms out here), so it
compacts easily and often requires mechanical aeration-- the Iowa soil
did not require much mechanical aeration and was calcium rich.

I still say it's a difficult soil to learn to grow on. It's hard to
work, and as one who was late to learn about shovel polishing of holes,
it can be unsuccessful just due to hole-digging technique. In fact,
the experience of trying to garden in my childhood home had really pushed
me away from the idea of ever trying to garden. It wasn't until I moved
to an area with a lovely, deep prairie topsoil that gardening became fun.
There, I could stand barefoot on bare soil and wiggle my feet a bit and
dig myself in ankle deep, the soil was that friable and loose. Stick a plant
in the ground and it grew.

But clay presents difficulties to most gardeners that a more balanced soil
does not... especially in the absence of good soil aeration. It can be
particularly tricky because of its cationic exchange properties... it
serves as an excellent buffer until it buffers no more.

Though clay holds soil moisture well, it's often not as available to the
plants as water in sandy soils, e.g.: http://ag.arizona.edu/turf/tips1095.html
which is a special problem in drought. And in comparing plant hardiness
in the soils in Iowa (USDA zone 5), I saw no real difference in frost
protection in clay vs. an organic loam: slope had a much larger effect.

David is, I believe, gardening on arid land clay in S. California;
a friend put her lawn in the front of the house in with (literally) pick and
shovel. When I lived there, my veggies were grown in raised beds to avoid
the salinized clay my house was built on (a failed orange grove).

Kay

On 10/08/2012 22:42, Kay Lancaster wrote:
On 10/08/2012 00:27, David Hare-Scott wrote:
Kay Lancaster wrote:
Treat clay soils with respect... they're difficult to grow on.

yes indeed.

D

A commonly held and vastly mistaken view, IMHO. Difficult to work
maybe. But they are not difficult to grow on at all, if you keep to a
couple of simple rules. Firstly, never try to plant anything when they

I, too, have been growing on clay for about 40 years now... first the clay
subsoil that was all the builders left when they stripped the top soil
and sold it at my childhood home in Iowa, and now out here in Oregon --
both yellow clays, though the Oregon clay is calcium poor, rocky and
nearly free of worms (there are no native worms out here),

Is that normal? I don't know anything about Oregon Clay, but would have
though that if there are almost no worms, more-or-less nothing could
grow as recycling of plant material couldn't take place, and aeration
would be non-existent. What happens with the native plants out there?
Or is the area basically a clay desert?

so it
compacts easily and often requires mechanical aeration-- the Iowa soil
did not require much mechanical aeration and was calcium rich.

It wasn't until I moved
to an area with a lovely, deep prairie topsoil that gardening became fun.
There, I could stand barefoot on bare soil and wiggle my feet a bit and
dig myself in ankle deep, the soil was that friable and loose. Stick a plant
in the ground and it grew.

But that's too easy. Don't you want a challenge? ;-)

Though clay holds soil moisture well, it's often not as available to the
plants as water in sandy soils, e.g.: http://ag.arizona.edu/turf/tips1095.html
which is a special problem in drought.

Interesting article. Grass, though...

--

Jeff

In article ,
Jeff Layman wrote:

On 10/08/2012 22:42, Kay Lancaster wrote:
On 10/08/2012 00:27, David Hare-Scott wrote:
Kay Lancaster wrote:
Treat clay soils with respect... they're difficult to grow on.

yes indeed.

D

A commonly held and vastly mistaken view, IMHO. Difficult to work
maybe. But they are not difficult to grow on at all, if you keep to a
couple of simple rules. Firstly, never try to plant anything when they

I, too, have been growing on clay for about 40 years now... first the clay
subsoil that was all the builders left when they stripped the top soil
and sold it at my childhood home in Iowa, and now out here in Oregon --
both yellow clays, though the Oregon clay is calcium poor, rocky and
nearly free of worms (there are no native worms out here),

Is that normal? I don't know anything about Oregon Clay, but would have
though that if there are almost no worms, more-or-less nothing could
grow as recycling of plant material couldn't take place, and aeration
would be non-existent. What happens with the native plants out there?
Or is the area basically a clay desert?

Here, 70 miles north of San Francisco, we have heavy clay. We scratched
at it for years before getting serious. The final solution was tilling
in sand (probably %5), and organic material. On this was planted rye
grass, and buckwheat, which break-up, and fills the soil with an amazing
amount of roots. Lastly, we keep the beds mulched, which allow the worms
to do most of the heavy work of turning, aerating (good soil is 50% air
spaces), and draining the soil.

For sure, plants like sequoias, oak, bay, and manzanita can punch
through the clay, but east of here in the town of Sonoma, there is
impenetrable hardpan (clay) a few feet below the top soil, which can
prevent perennials from finding the water they need.

Gotta work with wha'cha got.

so it
compacts easily and often requires mechanical aeration-- the Iowa soil
did not require much mechanical aeration and was calcium rich.

It wasn't until I moved
to an area with a lovely, deep prairie topsoil that gardening became fun.
There, I could stand barefoot on bare soil and wiggle my feet a bit and
dig myself in ankle deep, the soil was that friable and loose. Stick a
plant
in the ground and it grew.

But that's too easy. Don't you want a challenge? ;-)

Though clay holds soil moisture well, it's often not as available to the
plants as water in sandy soils, e.g.:
http://ag.arizona.edu/turf/tips1095.html
which is a special problem in drought.

Interesting article. Grass, though...

--
Welcome to the New America.
http://www.youtube.com/watch?v=hA736oK9FPg
or
E Pluribus Unum
Green Party Nominee Jill Stein & Running Mate, Cheri Honkala
http://www.democracynow.org/2012/7/13/green_party_nominee_jill_stein_running

Jeff Layman wrote:
On 10/08/2012 00:27, David Hare-Scott wrote:
Kay Lancaster wrote:
Treat clay soils with respect... they're difficult to grow on.

yes indeed.

D

A commonly held and vastly mistaken view, IMHO. Difficult to work
maybe. But they are not difficult to grow on at all, if you keep to a
couple of simple rules. Firstly, never try to plant anything when
they are soaking wet. Secondly, never try to plant anything when
they are bone dry. Clay is far more suited to growing many plants
than sandy soil; even those naturally found in sandy environments
will often more than just tolerate clay. I have grown heathers
without problem, and grown and fruited blueberries on clay (pH 6 -
6.5). I have even been able to move plants which are said to really
dislike being moved because a great lump of clay sticks to the roots,
and, to all intents and purposes, the roots really haven't been
disturbed at all. Try that with sandy or even "highly desirable"
loamy soil. The one plant I have given up with on clay soil is
grass. Where it is constantly wet, a lawn simply ends up a mess,
often with more moss than grass. The previous owner of the house I
moved in to had so much trouble he installed land drains, but even
those couldn't make a meaningful difference and in the end I had the
lawn removed (no great loss as I can't stand lawns anyway).
I live in the Sussex weald, and have been gardening on clay for over
25 years. And, believe me, Sussex clay is real clay. I have about 10
inches of claggy "soil" over a solid clay subsoil (solid with
ironstone lumps, that is. Even a pickaxe fails to penetrate some
parts. and I have to resort to a hammer drill if I want a deep hole).
The most difficult thing about gardening on clay is digging the damn
stuff; it is /very/ hard work. It even sticks to stainless steel
spades with a vengeance. And when dry, don't even bother with a
hammer drill - it's not worth the effort. Wait until it's workable
again.
But when it grows stuff, it is brilliant. It holds moisture; it holds
nutrients; it anchors. It tends to help withstand frosts much better
than lighter soils.

My situation is similar to yours, a layer of topsoil over plastic clay,
though I suspect my topsoil is naturally better. I agree that clay soil
holds water and nutrients well and can produce great crops. Every time the
region goes into drought I thank my stars for the clay underneath that acts
like a big sponge and keeps my pasture growing for months without rain.
Having had very sandy soil (that I was always trying to build up) and very
clayey soil that I have to break down I will take the clay.

BUT You have to have (or to make) actual soil. Clay by itself ( I mean the
plastic stuff you can mould into complex shapes) is hopeless. The process
of amending it takes years of effort and some skill. The choice of plants
has to be considered carefully as many will die in a wet spell due to lack
of drainage and it is impractical (for me anyway) to landscape the whole
garden for drainage and to amend all its soil to prevent the problem. As it
is all my fruit trees grow in mounds and my vege garden has raised beds with
drain paths running down-slope: at considerable effort and cost.

Clay is not for people who just want to plop something in the ground and see
it grow. I thought it interesting that in response to "Treat clay soils
with respect... they're difficult to grow on." you first deny that it is so
and then go on to explain all the difficulties that have. :-)


David

David Hare-Scott wrote:
....
My situation is similar to yours, a layer of topsoil over plastic clay,
though I suspect my topsoil is naturally better. I agree that clay soil
holds water and nutrients well and can produce great crops. Every time the
region goes into drought I thank my stars for the clay underneath that acts
like a big sponge and keeps my pasture growing for months without rain.
Having had very sandy soil (that I was always trying to build up) and very
clayey soil that I have to break down I will take the clay.

if you have a properly planted pasture with some
alfalfas and red clovers the tap roots from those
go down quite deep. even for more sandier soils
they can make the difference between a nice top
and barren brown scraggly yuck.

then again, also important is to not overgraze.


BUT You have to have (or to make) actual soil. Clay by itself ( I mean the
plastic stuff you can mould into complex shapes) is hopeless. The process
of amending it takes years of effort and some skill.

lasagna gardening isn't too bad, pile it on and
let time/worms/critters do most of the work. i
just wish i had enough space to do here that wasn't
surrounded by gravel pathways and prone to flooding
once in a while.


The choice of plants
has to be considered carefully as many will die in a wet spell due to lack
of drainage and it is impractical (for me anyway) to landscape the whole
garden for drainage and to amend all its soil to prevent the problem. As it
is all my fruit trees grow in mounds and my vege garden has raised beds with
drain paths running down-slope: at considerable effort and cost.

without the raised beds here many of the gardens out
back would be too soggy for too much of the spring to
get the soil warm enough. that is one of the problems
with clay that hasn't been mentioned yet (that it stays
cold longer). for some crops this is good, for others
not so good (tomatoes, peppers).


Clay is not for people who just want to plop something in the ground and see
it grow. I thought it interesting that in response to "Treat clay soils
with respect... they're difficult to grow on." you first deny that it is so
and then go on to explain all the difficulties that have. :-)

i keep working more organic material in when i
have a chance to do it and the garden is in between
crops/covercropping. still i'm not down very far in
some gardens because we keep rotating the heavier
feeders and i don't have a huge amount of extra
time and energy to dig in more stuff or hunt it down.
so far mixing in partially decayed wood chips along
with some sand if i have it has been the best results
for working, if i could convince myself to get a
breathing rig set up so i could fire more charcoal
in clay lined pits i think that was even a better
result for workability.

i agree with the points about proper drainage
being very important (or a good landscape design)
for clay. until i got the drainage situation
improved here it didn't make much sense to plant
certain gardens early.

for root vegetable beds out back (and the tulips)
i put in raised beds with french drains and drain
tiles to keep the water moving downwards or away
instead of perking the clay back up to the surface.
i put landscape fabric down too before i put the
topsoil/sandy topsoil mix in. i didn't want to
make it easy for the worms to channel into the
clay and mix it with the topsoil either. today
these were the only gardens that didn't get
flooded much.


songbird

"David Hare-Scott" wrote in message

Having had very sandy soil (that I was always trying to build up) and very
clayey soil that I have to break down I will take the clay.

I seem to recall an old gardener's saying of "Sand, heartache, Clay,
backache".